The present invention relates to a material for cutting tools, which has high toughness and strength, and excels in the resistance to both abrasion and plastic deformation.
Japanese Patent Kokai Publication No. 54-30209 discloses a cutting tool material obtained by adding AlN to a TiN-containing TiC base cermet. Although that cermet is known to have been improved with respect to cutting properties and mechanical properties, it is still not sufficient in strength since the base material per se still has a low strength, in spite of the fact that the AlN addition makes some contribution to increase in strength. At present, therefore, it is hardly used for heavy cutting, high impact milling or intermittent cutting. On the other hand, TiN base cermets excel in rupture toughness and stand up to thermal shock but, since the TiN per se shows unsatisfactory wetting compatibility with a bonding metal of iron group metals, they have such an increased number of pores that they are deficient in the strength and in the resistance to both abrasion and plastic deformation.